I. Field
The following description relates generally to wireless communications, and more particularly to providing indications within a common transaction concerning release of semi-persistently scheduled resources and transition to discontinuous reception (DRX) mode in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources (e.g., bandwidth, transmit power, . . . ). For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple access terminals. Each access terminal can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to access terminals, and the reverse link (or uplink) refers to the communication link from access terminals to base stations. This communication link can be established via a single-in-single-out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system.
MIMO systems commonly employ multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. A MIMO channel formed by the NT transmit and NR receive antennas can be decomposed into NS independent channels, which can be referred to as spatial channels, where NS≦{NT,NR}. Each of the NS independent channels corresponds to a dimension. Moreover, MIMO systems can provide improved performance (e.g., increased spectral efficiency, higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.
MIMO systems can support various duplexing techniques to divide forward and reverse link communications over a common physical medium. For instance, frequency division duplex (FDD) systems can utilize disparate frequency regions for forward and reverse link communications. Further, in time division duplex (TDD) systems, forward and reverse link communications can employ a common frequency region so that the reciprocity principle allows estimation of the forward link channel from reverse link channel.
Wireless communication systems oftentimes employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream may be a stream of data that can be of independent reception interest to an access terminal. An access terminal within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, an access terminal can transmit data to the base station or another access terminal.
In wireless data communication, receivers (e.g., of access terminals, . . . ) use significant power. For example, components of a receiver, such as a radio frequency (RF) transceiver, a high performance analog to digital (A/D) converter, and signal processing elements, can consume significant amounts of power. Accordingly, power saving mechanisms can be utilized to mitigate such power usage.
Various techniques can be leveraged within wireless communication systems to enhance power savings for access terminals. For instance, discontinuous reception (DRX) can be employed, such that an access terminal can be permitted to forgo monitoring a control channel for a period of time. Thus, the access terminal can be in DRX mode (e.g., sleep, . . . ) for a period of time and active mode (e.g., awake, monitoring the control channel, . . . ) for a disparate period of time. Another technique that can be employed by an access terminal is semi-persistent scheduling (SPS), which allows transfer of data on a shared channel (e.g., uplink, downlink, . . . ) without indicating presence of that data with a control channel. By way of illustration, a base station can assign SPS resources to an access terminal, and these resources can remain allocated to the access terminal until the base station disables such assignment, thereby releasing the SPS resources allotted to the access terminal. Conventional techniques, however, fail to coordinate transitioning an access terminal to DRX mode with release of SPS resources.